The BeagleBoard (http://beagleboard.org/ http://beagleboard.org/) may count as desktop. It's a tiny board with a 600 MHz Omap3 with 256MB RAM and the ability to

The BeagleBoard (http://beagleboard.org/ http://beagleboard.org/) may count as desktop. It's a tiny board with a 600 MHz Omap3 with 256MB RAM and the ability to play HD-Video. Power consumption is less than 3 Watt. I own one and it's fun to play with, although the display resolution is limited to 720p (maybe even 1280x1024) and a standard Linux desktop is pretty slow on it - Angstrom is better.